An Improved Tilt Angle Method and Its Application: A Case of Weigang Iron-Ore Deposit, Jiangsu
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摘要: 为解决Tilt梯度存在的"解析奇点"这一问题, 介绍了Tilt梯度位场边界识别方法, 并提出了改进算法.理论分析与模型计算表明, 改进的Tilt梯度方法继承了垂向一次导数与传统Tilt梯度以零值线识别边界的性质, 相对其他的导数类方法(如水平总梯度模等)能够更好地识别深部弱异常; 此外, 改进的Tilt梯度方法物理意义明确, 从理论上避免了方法的畸变性.对韦岗矿区磁异常分析表明, 除工区南侧由东向西分布的A、B、C 3个主体异常外, 尤其是工区5号线以北的弱异常D得到显著增强.结合钻孔资料以及磁异常反演结果, 认为弱异常D可能是由深部隐伏矿体的影响产生, 结合二度半人机交互反演推测矿体埋藏深度在1 000~1 200 m.6号线上的DH6-6见矿钻孔位于异常D的东侧, 该钻孔钻遇的薄层铁矿体位置与弱异常D的范围相吻合; 另外DH6-7未见矿钻孔位于该弱异常范围以外, 若向西在5号线以北布置钻孔, 则有见矿可能.Abstract: In order to slove the "singularity" problem of Tilt angle, an improved tilt angle method to detect the field source boundaries is proposed in this paper. Theoretical simulations reveal that improved Tilt angle method inherits the properties of the 1st order vertical derivative and traditional tilt gradient that identifies boundaries by zero value line and it is better for the deep weak anomalies identification than other methods such as the total module of horizontal gradient. Besides, the improved Tilt angle method avoids the abnormal degeneration due to its clear physical significance. Magnetic anomalies of the Weigang iron-ore deposit is analyzed and anomaly D is significantly enhanced except for three main anomalies of A, B, C, which indicates that the weak anomaly D is caused by deep concealed orebodies. The orebody depth is found as 1 000-1 200 m, based on the interactive inversion results of the 2.5 dimension. DH6-6 drilled hole is located in line 6, exactly on the east side of anomaly D, which coincides with the boring drilling of thin ore body. No-mine DH6-7 drilled hole is located at the outside of the weak anomaly area. It is possible that iron orebodies may be discovered if a drilled hole is arranged to the west and the north of Line 5.
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Key words:
- Tilt angle /
- boundary detection /
- crisis mining /
- Weigang iron-ore deposit /
- geophysics
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图 3 水平总梯度模(a)和垂向一次导数(b)
Fig. 3. Total module of horizontal gradient (a) and 1st order vertical derivative (b)
图 4 传统Tilt梯度结果(a)和改进的Tilt梯度结果(b)(黑色虚线框为识别边界)
Fig. 4. Results of traditional tilt gradient (a) and results of improved tilted gradient (b)
图 6 韦岗铁矿区-200 m基岩地质
粉色点代表见矿钻孔，黑色点代表未见矿钻孔
Fig. 6. Geology of Weigang iron deposit at -200 m depth
图 8 工区铁矿ΔZ磁测结果化到地磁极(化极磁异常)
Fig. 8. Reduction to the pole results of work area iron ore ΔZ magnetic survey
图 9 化极磁异常水平总梯度模
Fig. 9. Reduction to the pole results of Total module of horizontal gradient
图 12 5号线(a)和6号线(b)的地质剖面
Fig. 12. The geological profile of line No.5 (a) and line No.6 (b)
表 1 模型参数
Table 1. The model's parameters
模型编号 上底埋深(m) 方向长度x, y, z(m) 磁化强度(A/m) 磁化倾角(°) 磁化偏角(°) A 10 80, 100, 200 1.0 90 0 B 10 80, 100, 200 2.0 90 0 C 10 80, 100, 200 0.1 90 0 
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表 2 韦岗铁矿区岩矿石磁性参数统计结果
Table 2. Magnetic parameter statistics of rock and ore samples in Weigang iron mining area
岩矿石名称 块数 K×10-64π(SI) Jr×10-3(A/m) max min 平均 max min 平均 角砾岩 1 2.9 1.4 花岗闪长斑岩 7 3 392.8 2 841.4 3 117.9 812.0 527.5 636.1 闪长玢岩 6 1 706.0 22.8 523.1 326.8 2.8 96.1 矿化矽卡岩 2 109 180.0 74 860.0 92 020.0 108 547.0 48 271.0 78 409.0 矽卡岩 11 277.0 28.4 121.9 106.1 3.7 42.7 大理岩 8 26.9 2.0 9.6 109.2 3.2 28.0 磁铁矿 15 165 776.0 2 089.2 73 598.0 180 870.0 470.5 46 395.0
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[1] Bhattacharyya, B.K., 1965. Two-Dimensional Harmonic Analysis as a Tool for Magnetic Interpretation. Geophysics, 30(5): 829-857. doi: 10.1190/1.1439658 [2] Chen, J.G., Xiao, F., Chang, T., 2011. Gravity and Magnetic Anomaly Separation Based on Bidimensional Empirical Mode Decomposition. Earth Science—Journal of China University of Geosciences, 36(2): 327-335(in Chinese with English abstract). doi: 10.3799/dgkx.2011.034 [3] Cheng, Q.M., 2012. Ideas and Methods for Mineral Resources Integrated Prediction in Covered Areas. Earth Science—Journal of China University of Geosciences, 37(6): 1109-1125(in Chinese with English abstract). doi: 10.3799/dqkx.2012.118 [4] Gerovska, D., Araúzo-Bravo, M.J., 2006. Calculation of Magnitude Magnetic Transforms with High Centricity and Low Dependence on the Magnetization Vector Direction. Geophysics, 71(5): 121-130. doi: 10.1190/1.2335516 [5] Grauch, V.J.S., Cordell, L., 1987. Limitations of Determining Density or Magnetic Boundaries from the Horizontal Gradient of Gravity or Pseudogravity Data. Geophysics, 52(1): 118-121. doi: 10.1190/1.1442236 [6] Guan, Z.N., Yao C.L., 1997. Inversion of the Total Gradient Modulus of Magnetic Anomaly due to Dipping Dike. Earth Science—Journal of China University of Geosciences, 22(1): 81-85 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQKX701.015.htm [7] Hood, P.J., Teskey, D.J., 1989. Aeromagnetic Gradiometer Program of the Geological Survey of Canada. Geophysics, 54(8): 1012-1022. doi: 10.1190/1.1442726 [8] Hood, P., McClure, D.J., 1965. Gradient Measurements in Ground Magnetic Prospecting. Geophysics, 30(3): 403-410. doi: 10.1190/1.1439592 [9] Huang, L.P., Guan, Z.N., 1998. Discussion on "Magnetic Interpretation Using the 3-D Analytic Signal". Geophysics, 63(2): 667-670. doi: 10.1190/1.1444366 [10] Fairhead, J.D., Green, C.M., 2004. New Insights into Magnetic Derivatives for Structural Mapping. The Leading Edge, 23(2): 116-119. doi: 10.1190/1.1651454 [11] Li, X., 2006. Understanding 3D Analytic Signal Amplitude. Geophysics, 71(2): L13-L16. doi: 10.1190/1.2184367 [12] Liu, J.L., Li, Q.C., Zhao, B., 2007. New Detection Techniques of Geologic Boundaries Using Potential-Field Data and Its Application in the Shanxi Paleo-Structure Zone and Faults. Journal of Engineering Geology, 15(4): 569-574(in Chinese with English abstract). doi: 10.3969/j.issn.1004-9665.2007.04.024 [13] Liu Y.P., Wang Z.W., Du X.J., et al., 2012. Boundary Detection Method and Its Application in Hulin Basin. Journal of Jilin University(Earth Science Edition), 42(Suppl. 3): 271-278(in Chinese with English abstract). http://www.researchgate.net/publication/292293862_Boundary_detection_method_and_its_application_in_Hulin_Basin [14] Ma, G.Q., Huang, D.N., Yu, P., et al., 2012. Application of Improved Balancing Filters to Edge Identification of Potential Field Data. Chinese Journal of Geophysics, 55(12): 4288-4295(in Chinese with English abstract). doi: 10.6038/j.issn.0001-5733.2012.12.040 [15] Ma, G.Q., Li, L.L., 2012. Edge Detection in Potential Fields with the Normalized Total Horizontal Derivative. Computers & Geosciences, 41: 83-87. doi: 10.1016/j.cageo.2011.08.016 [16] Miller, H.G., Singh, V., 1994. Potential Field Tilt—A New Concept for Location of Potential Field Sources. Journal of Applied Geophysics, 32(2-3): 213-217. doi: 10.1016/0926-9851(94)90022-1 [17] Nabighian, M.N., 1972. The Analytic Signal of Two-Dimensional Magnetic Bodies with Polygonal Cross-Section: Its Properties and Use for Automated Anomaly Interpretation. Geophysics, 37(3): 507-517. doi: 10.1190/1.1440276 [18] Roest, W.R., Verhoef, J., Pilkington, M., 1992. Magnetic Interpretation Using the 3-D Analytic Signal. Geophysics, 57(1): 116-125. doi: 10.1190/1.1443174 [19] Sykes, M.P., Das, U.C., 2000. Directional Filtering for Linear Feature Enhancement in Geophysical Maps. Geophysics, 65(6): 1758-1768. doi: 10.1190/1.1444860 [20] Wang, W.Y., 2012. Spatial Variation Law of the Extreme Value Position of Analytical Signal Amplitude for Potential Field Data. Chinese Journal of Geophysics, 55(4): 1288-1299(in Chinese with English abstract). doi: 10.6038/j.issn.0001-5733.2012.04.024 [21] Wang, W.Y., Qiu, Z.Y., Yang, Y., et al., 2010. Some Advances in the Edge Recognition of the Potential Field. Progress in Geophysics, 25(1): 196-210(in Chinese with English abstract). doi: 10.3969/j.issn.1004-2903.2010.01.027 [22] Wang, Y.G., Wang, Z.W., Zhang, F.X., et al., 2012. Edge Detection of Potential Field Based on Normalized Vertical Gradient of Mean Square Error Ratio. Journal of China University of Petroleum, 36(2): 86-90, 96(in Chinese with English abstract). doi: 10.3969/j.issn.1673-5005.2012.02.014 [23] Xia, L.Y., Wu, H.N., Bai, G.J., et al., 2008. Research on Enhancing Weak Signal Technology and Recognition of Linear Structures Using Aerial-Magnetic Data in the Qaidam Basin. Progress in Geophysics, 23(4): 1058-1062(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQWJ200804008.htm [24] Yu, Q.F., Lou, H., 1994. Locating the Boundaries of Magnetic or Gravity Sources Using Horizontal Gradient Anomalies. Computing Techniques for Geophysical and Geochemical Exploration, 16(4): 363-367 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-WTHT404.013.htm [25] Zhang, H.L., Liu, T.Y., Yang, Y.S., 2011. Calculation of Gravity and Magnetic Source Boundary Based on Anisotropy Normalized Variance. Chinese Journal of Geophysics, 54(7): 1921-1927(in Chinese with English abstract). doi: 10.3969/j.issn.0001-5733.2011.07.026 [26] Zhao, X.G., Wu, H.N., Bai, G.J., et al., 2008. Magnetic and Gravity Data Processing Method and Imaging Techniques for Faulted Structure Interpretation. Progress in Geophysics, 23(2): 414-421(in Chinese with English abstract). http://www.oalib.com/paper/1697990 [27] 陈建国, 肖凡, 常韬, 2011. 基于二维经验模态分解的重磁异常分离. 地球科学——中国地质大学学报, 36(2): 327-335. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201102019.htm [28] 成秋明, 2012. 覆盖区矿产综合预测思路与方法. 地球科学——中国地质大学学报, 37(6): 1109-1125. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201206005.htm [29] 管志宁, 姚长利, 1997. 倾斜板体磁异常总梯度模反演方法. 地球科学——中国地质大学学报, 22(1): 81-85. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX701.015.htm [30] 刘金兰, 李庆春, 赵斌, 2007. 位场场源边界识别新技术及其在山西古构造带与断裂探测中的应用研究. 工程地质学报, 15(4): 569-574. doi: 10.3969/j.issn.1004-9665.2007.04.024 [31] 刘银萍, 王祝文, 杜晓娟, 等, 2012. 边界识别技术及其在虎林盆地中的应用. 吉林大学学报(地球科学版), 42(增刊3): 271-278. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ2012S3032.htm [32] 马国庆, 黄大年, 于平, 等, 2012. 改进的均衡滤波器在位场数据边界识别中的应用. 地球物理学报, 55(12): 4288-4295. doi: 10.6038/j.issn.0001-5733.2012.12.040 [33] 王万银, 2012. 位场解析信号振幅极值位置空间变化规律研究. 地球物理学报, 55(4): 1288-1299. doi: 10.6038/j.issn.0001-5733.2012.04.024 [34] 王万银, 邱之云, 杨永, 等, 2010. 位场边缘识别方法研究进展. 地球物理学进展, 25(1): 196-210. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWJ201001029.htm [35] 王彦国, 王祝文, 张凤旭, 等, 2012. 基于均方差比归一化垂向梯度法的位场边界检测. 中国石油大学学报: 自然科学版, 36(2): 86-90, 96. doi: 10.3969/j.issn.1673-5005.2012.02.014 [36] 夏玲燕, 吴汉宁, 柏冠军, 等, 2008. 柴达木盆地航磁资料微弱信息增强技术研究及在线性构造识别中的应用. 地球物理学进展, 23(4): 1058-1062. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWJ200804008.htm [37] 余钦范, 楼海, 1994. 水平梯度法提取重磁源边界位置. 物探化探计算技术, 16(4): 363-367. https://www.cnki.com.cn/Article/CJFDTOTAL-WTHT404.013.htm [38] 张恒磊, 刘天佑, 杨宇山, 2011. 各向异性标准化方差计算重磁源边界. 地球物理学报, 54(7): 1921-1927. doi: 10.3969/j.issn.0001-5733.2011.07.026 [39] 赵希刚, 吴汉宁, 柏冠军, 等, 2008. 重磁异常解释断裂构造的处理方法及图示技术. 地球物理学进展, 23(2): 414-421. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWJ200802015.htm -
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